Simanaitis Says
On cars, old, new and future; science & technology; vintage airplanes, computer flight simulation of them; Sherlockiana; our English language; travel; and other stuff
OWLS AND WRINKLY FINGERS
TWO COMPLETELY unrelated items jumped out of recent Science magazines, published by the American Association for the Advancement of Science. One details how owls can twist their heads so far around. The second describes why our fingertips get all wrinkly after extended soaking.
Really now, how could one not want to know these things?
The owl item, in Science, 1 February 2013, was First Place Winner in the Poster & Graphics category of the 2012 Visualization Challenge, a competition organized by Science magazine and the National Science Foundation.
The title of the poster is quite a mouthful, “Adaptations of the Owl’s Cervical & Cephalic Arteries in Relation to Extreme Neck Rotation.”
Arteries carry blood around the body from the heart (veins circulate it back to the heart). Cervical and cephalic arteries are in the neck and head, respectively.
Image from Science, 1 February 2013.
And, indeed, an owl’s neck is capable of extreme rotation—as much as 270 degrees, three-quarters of a complete rotation, in either direction.
The bird evolved this capability because of its eyes, specially adapted to low light. They’re really large and tubular, not spherical like ours. Hence, the owl’s eyes don’t rotate; instead, the owl twists its whole head.
Evolution gave the owl’s neck 14 vertabrae, twice the human neck’s count. Holes for the arteries in these vertebrae are oversize; this, so there’s no crimping in extreme twist. What’s more, the arteries align with the neck’s axis of rotation for this same reason.
Also, researchers conjecture that these arteries have cushioning to protect them as well as reservoirs to stabilize blood flow.
All of these are artfully displayed in the prize-winning poster. (Scale it up for a good look.)
Moving to human development and the 11 January 2013 issue of Science, researchers at England’s Newcastle University have suggested an evolutionary benefit to the pale wrinkles our fingertips get after an extended soaking.
What causes hands (as well as feet) to wrinkle after a good soaking ? Image from www.psychsciencenotes.blogspot.com.
It was long thought that these wrinkles were caused by osmosis-induced swelling in the skin’s outer layer. However, this latest research indicates that the puckering is produced by the autonomic nervous system. It occurs on hair-free skin of the hands, fingers, feet and toes—and nowhere else on the body.
The proposed evolutionary benefit is enhanced grip on objects that are wet or submerged.
What’s more, researchers tested this hypothesis in a clever manner. Test subjects were timed as they manipulated 45 submerged objects—glass marbles, fishing weights and the like—from bin to bin though a postage-stamp opening.
When the test subjects had wrinkly fingers—induced by soaking their hands in hot water for 30 minutes—they completed the task about 12 percent quicker than when their hands hadn’t been pre-soaked. When performing the same task with dry objects, wrinkly fingers showed no benefit. ds
© Dennis Simanaitis, SimanaitisSays.com, 2013
Simanaitis Says 